Tapioca is a starch extracted from cassava root. It consists of almost pure carbs and contains very little protein, fiber, or nutrients. Tapioca has become popular recently as a gluten-free alternative to wheat and other grains. Tapioca is a starchy product that derives from cassava tubers. These tubers are native to Brazil and much of South America. Tapioca is available in a variety of forms, including flour, meal, flakes, and pearls.